Elevator safety device



06L 6, 1942. RlSSLER 2,298,167

ELEVATOR SAFETY DEVICE Filed March '7, 1942 2 Sheets-Sheet l WITNESSES: INVENTOR ATTORNEY Patented Oct. 6, 1942 U N i T E ST TES- Westinghouse Electric Elevator Company,

Jersey City, N. J., a corporation of Illinois Application March 7-, 1942, Serial No. 433,811

15 Claims.

My invention relates to safety devices for elevator cars and, more particularly, to such safety devices as are mounted on the bottom of the car in position to engage the elevator guide rails and stop the car when it starts to fall or run away downwardly.

One object of my invention is to provide a safety device which will eliminate the necessity for a buffer in the elevator pit.

Another object is to provide a safety device which will bring the car to rest gently with a uniform speed of retardation and without excessive retardation if it starts to fall or exceeds a predetermined down speed.

Another object is to provide a safety device which will stop the car without causing it to chatter and Which will maintain the car platform in approximately its level position regardless of the distribution of the load thereon when a safety stop is effected.

A further object is to provide an elevator car safety device which will, after it has been operated to stop the car, be self-releasing when the car is moved upwardly.

A still further object is to provide an elevator safety device which shall be simple and effective in operation and inexpensive to manufacture, install and maintain in ready operative condition after installation.

For a better understanding of my invention, reference may be had to the accompanying drawings, in which:

Figure 1 is a view in side elevation of an elevator installation embodying my improved safety device as applied to the bottom of the car;

Fig. 2 is a view taken along the line IIII of Fig. 1;

Fig. 3 is an enlarged view in front elevation of the upper shackle and inertia spring clamp on the governor rope in Fig. 1;

Fig. 4 is a bottom plan view of the clamp on the governor rod in Fig. 3;

Fig. 5 is a view taken along the line V- J of Fig. 1;

Fig. 6 is an enlarged view in side elevation of the mounting of the brake shoes for the brake drum embodied in Fig. 1;

Fig. 7 is a View taken along the line VlI-VII of Fig. 1; and V Fig. 8 is a view in front elevation and partly in section of my improved safety device along the line VIII-VIII in Fig. '7.

Referring more particularly to my invention, I have illustrated an elevator car C as mounted for operation between a pair of vertical guide i;

rails l9 and H by guide shoes l2 on the upper part of the car and a pair of guide shoes 14 and [5 on the lower part of the car. The guide rails Iii and II may be mounted in vertical position in the hatchway for the car represented by the concrete flooring H5 at the bottom or pit of the elevator. The car may be operated in the usual manner by hoisting cables, hoisting drums, etc;, not shown.

In accordance with my invention, I have provided a safety device 28 mounted underneath the car for stopping it if it should fall or exceed a predetermined down acceleration or down speed and also for gently bringing it to rest when it moves within a predetermined distance of the bottom of the elevator pit.

The safety device comprises a pair of brake shoes 2| and 22 mounted on the under portion of the car in position to engage a brake drum 23 also mounted on the under portion of the car and which will be caused to rotate when the car exceeds a predetermined down speed. The brake shoe 2! is pivotally mounted on the inner end of a brake lever 24 pivotally mounted in a lug 25 fixed on the inner face of a channel member 25 secured to the under frame 21 of the car. The outer end of the brake lever 24 is pivotally connected to the inner end of an I-bolt 28, the outer end of which extends freely through an aperture 3| in the channel member 25 and which is provided on its outer end with a tension nut 29 which holdsa compression coil spring 30 between itself and the channel member 25. The compression spring is coiled around the I-bolt 2B and exerts an outward pull on the I-bolt to apply the brake shoe 2| to the drum 23 with a predetermined friction value, which may be set as desired by rotating the nut 29.

The brake shoe. 22 is mounted in the same manner as the brake shoe 2! on a channel iron 32 mounted in parallel relation to the channel iron 26 on the under frame of the car.

The pressure of the brake shoes 21 and 22 against the brake drum 23 should be adjusted to such value that rotation of the brake drum under the pressure of the shoes will bring the car to rest with a predetermined speed of deceleration, if the car starts to fall or run away downwardly sufficiently to set the safety device into operation.

The means for causing rotation of the brake drum to decelerate the car when the safety device is set into operation comprises a pair of shafts 33 and 34, a pair of rack wheels 35 and 35, a pair of rack rails or stopping blocks 31 and.

38, and a pair of safety clutches 39 and 39a operated by a governor rope 46 when the car falls or runs away downwardly.

The rotatable shafts 33 and 34 are mounted in horizontal position underneath the car by means of a plurality of bearing brackets 42, 43, 44 and 45. The brake drum 23 is rotatably mounted on the inner ends of the shafts 33 and 34 at approximately the center of the car. A pair of brake clutches 46 and 41 are slidably mounted on the shafts 33 and 34 and keyed thereto so as to rotate therewith.

The clutch member 41 is provided with ratchet teeth 48 on its inner face to engage cooperating ratchet teeth 49 on the right-hand face of the hub of the brake drum (see Figs. '7 and 8). A coiled compression spring 56 is mounted on the shaft 34 and concentric therewith between the clutch member 41 and the supporting bracket 44 for the purpose of biasing the clutch member 41 toward the hub of the brake drum. The clutch member 46 is similarly provided with ratchet teeth for engaging ratchet teeth 52 on the left-hand faceof the brake drum hub. A compression spring 53 is mounted on the shaft 33 and concentric therewith between the bracket 43 and the clutch member 46 to bias the clutch member toward the brake drum hub. The cooperating ratchet teeth between the brake drum and the clutch members should be so slanted and shaped that rotation of the shafts 33 and 34 in the direction of the arrow 55 (counterclockwise in Fig. 1) will rotate the brake drum with them against the friction of the brake shoes 2| and 22 but will cause the ratchet teeth on the clutch members to slip over the ratchet teeth on the brake drum without rotating the drum when the shafts 33 and 34 are rotated in the opposite direction. The slip in the reverse direction will occur because the compression springs 53 and 54 will permit the clutch members 46 and 41 to move outwardly away from the brake drum while the ratchet teeth are passing each other in the reverse direction.

The rack wheels or pinion gears 35 and 36 are firmly fixed on the outer ends of the shafts 33 and 34 in position to mesh with the rack rails 31 and 38, respectively. It will be observed that if the rack wheel 36 is moved down along the rack rail 38, that action will cause rotation of the pinion 36 in the counterclockwise direction indicated by the arrow 55. In like manner, the downward movement of the rack wheel 35 against the rack rail 31 will cause rotation of the shaft 33 in the same direction as the direction of rotation of the shaft 34.

Referring now to the guide rail clutch or clamp 39 (see Fig. 1), it will be observed that the rack rail 38 has a clamping body 51 provided with a slot or recess 58 designed to fit the guiding portion 59 of the guide rail II and slide along it without frictionally engaging it. The upper end of the rack rail 38 is provided with a lug 69 which rests in a notched portion of the upper left-hand side of the guide shoe l4 so as to limit the downward movement of the rack rail. Normally, the weight of the rack rail 38 causes it to hang on the guide shoe l4 and be carried by the car as the car moves up and down along the guide rail. In this position, the pinion 36 normally meshes with the teeth in the upper portion of the rack rail. The upper end of the rack rail rests on the top of the guide shoe !4 and the upper part of its clamp member 51 faces the lower part of the shoe I4, thereby providing a limiting means or lost-motion connection between the rack rail and the car which limits the relative motion between them to the distance the car can decelerate before it engages and stops on the upper face of the clamping member 51 when a safety stop is made.

The guide rail clamp member 51 is provided with an inclined recess 6| facing the guiding surface of the guide rail H for the reception of a clutch roller 62. The upper surface of the recess 61 is inclined toward the guide rail in such manner that when the roller 62 is lifted while the rack rail is moving downwardly, it will be forced into contact with the uide rail and thereby wedge the rack rail tightly against the guide rail and thus stop its down movement. When the rack rail is clamped against the guide rail by the action of the roller, further downward movement of the car will carry the pinion 36 down along the rack rail 38 thus rotating the pinion and the shaft 34 to turn the brake drum 23 against the action of the brake shoes 2! and 22.

The means for raising the roller 62 in the recess 6| to effect the clamping action comprises a lever 63 having a finger 66 (Fig. 5) disposed underneath the roller and which is fixed on one end of a rod 65 rotatably mounted in extension members 64 on the clamping members 51 and 51a.

The rack rail 31 and its rail clamping member 510. are constructed in the same manner as the rack rail 38 and its clamping member 51, with a lever 63a. for raising its roller to lock it on the guide rail. The lever 53a is fixedly mounted on the left-hand end of the rod 65 (Fig. 5) so that operation of either lever 63 or 63a will cause operation of the other.

The governor rope 40 comprises a cable portion 10 and alift or governor rod portion 1!. The cable portion passes over a governor sheave 12 at the upper end of the hatchway and around a tension sheave 13 at the lower end of the hatchway and is connected by an upper shackle 14 to the upper end of the rod 1-! and by a lower shackle 14a. to the lower end of the rod. The lift rod is pivotally connected near its lower end to the lever 63 so that raising the rod relative to the car will raise the levers 63 and 63a.

The governor rope is connected to the car by a bracket 15, one end of which is secured to the car top beam and the other end of which slidably embraces the rod H just below the upper shackle 14 and above a tension spring 16. When the car moves in normal operation, the bracket '15 carries the governor rope along with the car, thereby rotating the governor sheave 12.

The rotation of the governor sheave serves to operate a suitable governor, not shown, which will cause the rope to be clamped and stopped against further movement when the car exceeds a predetermined down speed either by reason of falling or running away. Inasmuch as governors of this character are old and well known in the art, no further description thereof will be given. If further information respecting such governors is desired, it may be secured from Patent No. 1,957,311, issued May 1, 1934, on Inertia type governor, and assigned to the Westinghouse Electric Elevator Company.

If the car exceeds a predetermined down speed, the governor (not shown) will stop the governor rope as the car goes down, thus holding the levers 63 and 63a to stop the car. The spring 16 is provided to further increase the safety of the system, and it should be of such. strengthv that, should the hoisting. cable break, the inertia of the governor sheave, the tension sheave. and the governor cable will compress the spring. to such an extent that the relative movement of the car with respect to the lift rod H will set the safety to stop the car.

In order to secure full cooperation of the inertia spring 16 with the other parts of my invention, I mount a slidable collar or clamp 18. on the lift rod underneath the spring. The frictional engagement of the clamp 18 with the rod ll may be set at a predetermined value by ad-- justing compression springs 19 on the clamp. A pair of stop members 80 (Fig. 3') are mounted on the underside of the bracket to engage the collar 18 so that the rod II will be forced to slide through it after the spring 16 is compressed at predetermined distance when the safety is set. The length of this sliding zone should be approximately equal to the travel of the car during the car decelerating action of the brake drum when the safety is set.

If this sliding zone were not provided, the down movement of the car, after the setting of the governor or the overcoming of theinertia spring, would drag the governor cable and thereby damage the governor, the cable or the bracket.

A lost motion connector such as a chain 8i having its one end attached to the bracket 15 on the car and its other end attached to the clamp 18 on the governor rod is provided for dragging the clamp 78 back along the governor rod II when the safety is restored to its normal position, if the rod 1| has been forced upwardly through the clamp to a greater than normal extent in a setting operation of the safety.

A switch 82 having its one contact mounted on the car platform 2'! and its other contact mounted on the governor rod H is provided for stopping the motor (not shown) when any usual upward movement of the governor rod occurs. The switch should be connected in the control circuit of the elevator hoisting motor (not shown) and so positioned that any upward movement of the governor rod 1! relative to the car will open the contacts and thereby stopthe hoisting motor, thus preventing the possibility of slack cables. After the cause of the unusual upward movement of the governor rod is investigated, the car may be moved upwardly to restore the safety parts and the switch 82 to normal condition by operating the slow speed switches (not shown) by hand or by temporarily shorting the contacts.

In addition to providing for operating the safety device to bring the car to rest when it falls or starts to run away, I have provided a pair of bumpers mounted in the pit of the hatchway for causing the safety device to stop the car gently in case it approaches too closely to the bottom of the pit.

The bumper 83 is disposed at the base of the guide rail H9 in posit-ion to be struck by the lower end of the rack rail 38 and the bumper 84 is disposed adjacent to the bottom of the guide rail l I to be struck by the bottom of the rack rail as when the car approaches within a predetermined distance of the bottom of the pit, for the purpose of decelerating the car and stopping it before it strikes the floor of the pit.

From the foregoing construction, it will be realized that if the car falls or starts to run away downwardly, its increased speed will cause the governor to stop movement of the governor rope ill. Further down movement of the car after th governor rope is stopped carries the inclined surfaces of the clamp bodies 5,! and 5.7a down against the rollers 62 held by the free ends of the levers 63 and 63a. Ihis action causes the rollers to wedge between the inclined surfaces of the clamp bodies and the guide rails thereby clamping the rack rails 31 and 38 against the guide rails I9 and II and thus stopping their down movement along the guide rails. Inasmuch as the car is still moving downwardly, its continued down operation moves the rack wheels 35 and 36 down along the rack rails 31 and 38, thusv rotating the shafts 33 and 34, on which the rack wheels are fixed, in the direction indicated by the arrow 55. This direction of rotation causes the. clutch members is and 51', by reason of their ratchet teeth, to rotate the brake drum 23 in the same direction against the pressure of the brake shoes 2| and 22. The force set up by the friction of the brake drum and brake shoes causes the car to decelerate to a gentle stop at a predetermined rate of deceleration. If the predetermined pressure of the brake drum should not be sufficient to stop the car, the guide shoes l4 and 15 will come to rest on the upper surfaces of the rack rails 31 and 38 now clamped to the guide rails l9 and II, and will thereby prevent any further down movement of the car.

The safety device may be released simply by raising the car sufficiently to cause the clamping rollers in the rail clamping devices to fall downwardly in the recesses El out of engagement with the guide rails. Normally the weight of the clamping members 51 and 51a will be such that they will move the rack rails 31 and 38 downwardly as the car moves upwardly and thus operate the ratchet wheels 35 and 36 to rotate the shafts 33 and 34 in a direction opposite to that indicated by the arrow 55. When this action occurs, the ratchet teeth between the clutches and i! and the brake drum 23 will slip under the action of the clutch springs 53 and 56 because the brake drum 23 is resisting movement by reason of the pressure of the brake shoes 2| and 22 against its braking surface.

run away and that it makes a normal down trip except that it does not stop at the lower terminal and continues on down to the lower end of the hatchway, then, as the car approaches Within a predetermined distance of the bottom of the pit, the lower ends of the rack rails 31 and 38 engage the upper ends of the bumpers 83 and 85 and are stopped thereby. As the car continues on down, it moves the rack wheels down along the. rack rails thereby rotating the shafts 33 and 3 and the brake drum 24 against the friction of the brake shoes 2i and 22. The braking effect produced by the friction between the brake drum and the brake shoes decelerates the car to a stop on the upper ends of the bumper posts 83 and 84.

When the car is raised to make an up trip, the weight of the rack. rails will cause them to drop to their lowermost position, thus reversing the direction of rotation of the rack wheels and the brake clutches 35 and ii. By reason. of the slant of the ratchet teeth between the clutches 46 and i7 and the teeth of the brake drum, the friction of the brake shoes on the brake drum will hold it while the brake clutches slip until the rack rails resume their normal position depending from the car and ready for the next operation of the safety.

From the foregoing construction, it will be observed that I have provided a safety device which will permit the elevator car to be stopped without causing it to chatter or become unbalanced, that uniform retardation of the car will be obtained because of the predetermined brake action, that the safety cannot be set to stop the car on up car motion and that it can be adapted to suit any desired car speed with very simple mechanical modifications. It will also be apparent that a governor of the simplest type may be employed, because the down pull on the governor cable stops as soon as the rail racks grip the guide rails. Furthermore, the safety device may be readily adapted to be set upon sudden acceleration of the car in the down direction by the inertia of the governor cable under the action of the inertia spring.

It will also be apparent that the use of a pair of bumper posts in the pit provides a means for setting the safety device when the car approaches too closely to the bottom of the elevator pit and thereby eliminates the necessity for a buffer in the pit.

Although I have illustrated and described only one specific embodiment of my invention, it is to be understood that modifications thereof and changes therein may be made without departing from the spirit and scope of the invention.

I claim as my invention:

1. A safety device for an elevator car operable between a pair of guide rails in a hatchway comprising a pair of shafts, means for rotatably mounting the shafts on the bottom of the car in approximately horizontal alignment with each other, a brake drum rotatably mounted on the adjacent inner ends of the shafts, said brake drum having ratchet teeth on the outer faces of its hub, a clutch member slidably mounted on the inner end portion for each shaft and having ratchet teeth disposed to engage the ratchet teeth on the hub 'of the brake wheel, means for causing the clutch members to rotate with the shafts, a clutch spring mounted adjacent to each clutch member on each shaft for biasing the ratchet teeth of that clutch member into engagement with the ratchet teeth on the hub of the brake drum, said ratchet teeth being angularly disposed to rotate the brake drum with the shafts when they are rotated in one direction and to slip when the shafts are rotated in the opposite direction, a pair of brake levers mounted on the car, a brake shoe mounted on the inner end of each brake lever, a pair of brake springs for connecting the outer ends of the brake levers to the car to bias the brake shoes into braking engagement with the brake drum, a bolt associated with each brake spring for adjusting the braking pressure of that spring to a predetermined value, a rack wheel fixed on the outer end of each shaft, a pair of rack rails slidably mounted in approximately vertical position on the car adjacent to the guide rails for engaging the rack wheels, means for limiting the movements of the rack rails, a guide rail clamp for each rack rail, a governor rope for the hatchway, for rotating the brake drum against the brake shoes.

2. A safety device for an elevator car operable between a pair of guide rails in a hatchway comprising a pair of shafts, brackets for rotatably mounting the shafts on the bottom of the car in approximately horizontal alignment with each other, a brake wheel rotatably mounted on the adjacent inner ends of the shafts, said brake drum having ratchet teeth on the outer faces of its hub, a clutch member slidably mounted on the inner end portion of each shaft and having ratchet teeth disposed to engage the ratchet teeth on the hub of the brake wheel, means for causing the clutch members to rotate with the shafts, a clutch spring mounted adjacent to each clutch member on each shaft for biasing the ratchet teeth of that clutch member into engagement with the ratchet teeth on the hub of the brake drum, said ratchet teeth being 7 angularly disposed to rotate the brake drum with the shafts when they are rotated in one direction and to slip when the shafts are rotated in the opposite direction, a pair of brake levers mounted on the car, a brake shoe mounted on the inner end of each brake lever, a pair of brake springs for connecting the outer ends of the brake levers to the car to bias the brake shoes into braking engagement with the brake drum, a bolt associated with each brake spring for adjusting the braking pressure of that spring to a predetermined value, a rack wheel fixed on the outer end of each shaft, a pair of rack rails slidably mounted in approximately vertical position on the car adjacent to the guide rails for engaging the rack Wheels, means for limiting the movements of the rack rails, a guide rail clamp for each rack rail, and a governor rope for operating the clamps to lock the rack rails to the guide rails when the car exceeds a predetermined down speed whereby further down movement of the car will cause the rack wheels to rotate the brake drum against the brake shoes to decelerate the car to a stop.

3. A safety device for an elevator car operable along a guide rail in a hatchway comprising a shaft, means for rotatably mounting the shaft on the bottom of the car, a brake drum rotatably mounted on one end of th shaft, said brake drum having ratchet teeth on its hub, a clutch member slidably mounted on the inner end portion of the shaft and splined on the shaft to rotate therewith and having ratchet teeth disposed to engage the ratchet teeth on the hub of the brake drum, a clutch spring mounted adjacent to the clutch member for biasing the ratchet teeth of the clutch member into engagement with the ratchet teeth on th brake drum, said ratchet teeth being angularly disposed to rotate the brake drum with the shaft when it is rotated in one direction and to slip when the shaft is rotated in the opposite direction, a brake lever mounted on the car, a brake shoe mounted on the inner end of the brake lever, a brake spring connecting the outer end of the brake lever to the car for biasing the brake shoe into braking engagement with the brake drum, a bolt associated with the brake spring for adjusting the braking pressure of the spring to a predetermined value, a rack wheel fixed on the outer end of the shaft, a rack rail slidably mounted in approximately vertical position on the car adjacent to the guide rail in position to engage the rack wheel, means fOr limiting the movement of the rack rail, a guide rail clamp for the rack rail, and a governor rope for operating the clamp to lock the rack rail to the guide rail when the car exceeds a predetermined down speed whereby further down movement of the car will cause th rack wheel to rotate along the rack rail and thereby rotate the brake drum against the brake shoe to decelerate the car, and a stop member on the car for engaging the rack rail to stop relative movement between the car and the rack rail after the car has mov d downwardly along the rack rail a predetermined distance.

4. A safety device for an elevator car operable along a guide rail in a hatchway comprising a brake drum rotatably mounted on the car, a brake shoe mounted on the car, a spring for biasing the brake shoe against the brake drum with a predetermined pressure, a brake drum rotating mechanism, and means responsive to a predetermined down speed of the car for operating said mechanism to rotate the brake drum against the friction of the brake shoe upon further 'dOWII movement of the car to thereby decelerate th car.

5. A safety device for an elevator car operable along a guide rail in a hatchway comprising a brake drum rotatably mounted on the car, a brake shoe mounted on the car, means for biasing the brake shoe against the brake drum with a predetermined pressure, a rack member carried by the car and disposed to move freely along the I uide rail during normal operation of the car, means responsive to a predetermined down speed of the car for clamping th rack member to the guide rail, and means responsive to the clamping of the rack member to the guide rail and further down movement of the car for rotating the brake drum against the brake shoe to decelerate the car.

6. In an elevator installation in a hatchway, an elevator car, a pair of guid rails for the car, a device for stopping the car, a safety means responsive to a predetermined down speed of the car for clamping the stopping device to a guide rail to stop the car, a brake drum and brake shoe mounted on the car and disposed in frictional engagement with each other, and means responsive to the clamping of the said device to the guide rail and to down movement of the car for producing relative movement between the drum and the shoe to decelerate the car.

'7. In an elevator installation in a hatchway, a car, a pair of guide rails for the car, a stopping block having a lost motion connection with the car, means responsive to the car moving downwardly at greater than a predetermined down speed or beyond a predetermined point in the hatchway for preventing further down movement of said block, a brake shoe mounted on the car, a brake drum mounted on the car in engagement with the brake shoe, and means responsive to the stopping of the block and further down movement of the car thereafter to rotate the brake drum to decelerate the car.

8. A safety device for an elevator car operable along a guide rail in a hatchway comprising a shaft horizontally disposed on the under body of the car, a brake drum mounted on the inner end of the shaft, a brake shoe mounted on the car, means for biasing the brake shoe into a predetermined frictional engagement with the drum, a rack rail supported with a lost-motion connection on the car, safety means responsive to movement of the car downwardly beyond a predetermined point in the hatchway or at a predetermined speed for arresting the down movement of the rack rail, and a rack wheel fixed on the outer end of the shaft and in mesh with the rack rail whereby continued down motion of the car after the rack rail is arrested causes rotation of the rack wheel and the brake drum to decelerate the car.

9. A safety device for an elevator car operable along a guide rail in a hatchway comprising a shaft horizontally disposed on the under body of the car, a brake drum mounted on the inner end of the shaft, a brake shoe mounted on the car, means for biasing the brake shoe into a predetermined frictional engagement with the drum, a rack rail supported with a lost-motion connection on the car, a bumper mounted .in the lower end of the hatchway in position to engage and stop the rack rail when it is moved down by the car nearing the bottom of the hatchway, and a rack wheel fixed on the outer end of the shaft and in mesh with the rack rail whereby further down movement of the car will drive the rack wheel along the rack rail and thus rotate the brake drum to decelerate the car at a predetermined rate.

10. A safety device for an elevator car operable along a guide rail in a hatchway comprising a shaft horizontally disposed on the under body of the car, a brake drum mounted On the inner end of the shaft, a brake shoe mounted on the car, means for biasing the brake shoe into a predetermined frictional engagement with the drum, a rack rail supported with a lost-motion connection on the car, a safety means responsive to a predetermined down speed of the car for clamping the rack rail to the guide rail, and a rack wheel fixed on the outer end of the shaft and in mesh with the rack rail whereby further down movement of the car after the rack rail is clamped to the guide rail moves the rack wheel down along the rack rail and thereby rotates the drum against the shoe to decelerate the car.

11. In an elevator in a hatchway, a car, a pair of guide rails for the car, a device for stopping the car, a governor rope for setting the stopping device into operation to first decelerate the car and then stop it, a bracket on the car, for moving the governor rope with the car during its normal operation, an inertia spring, a clamp disposed on the governor rope for mounting the spring on the governor rope to engage the bracket when the car is moving downwardly, resilient means for holding the clamping pressure of the clamping device on the governor rope to a predetermined value to permit it to slide on the governor rope when the pull of the bracket on the governor rope exceeds a predetermined value, for the purpose of preventing damage to the safety device, and means for adjusting the value of the pressure exerted by the resilient means.

12. In an elevator in a hatchway, a car, a pair of guide rails for the car, a safety device for stopping the car, a governor rope for setting the stopping device into operation to first decelerate the car and then stop it, a bracket on the car for moving the governor rope with the car during its normal operation, an inertia spring, a clamp disposed on the governor rope for mounting the spring on the governor rope to engage the bracket when the car is moving downwardly, and means for adjusting the pressure of the clamp on the governor rope to a predetermined value which will permit it to slide on the governor rope when the pull on it exceeds a predetermined value.

13. In an elevator in a hatchway, a car, a pair of guide rails for the car, a safety device for stopping the car, a governor rope for setting the stopping device into operation to first decelerate the car and then stop it, a bracket on the car for moving the governor rope with the car during its normal operation, an inertia spring, a clamp disposed on the governor rope for mounting the spring on the governor rope to engage the bracket when the car is moving downwardly, means for adjusting the pressure of the clamp on the governor rope to a predetermined value which will permit it to slide on the governor rope when the pull on it exceeds a predetermined value, and a lost motion connector associated with the clamp for assisting in restoring the clamp to its correct position when the safety device is restored to its normal condition after being operated to decelerate the car.

14. In an elevator in a hatchway, a car, a pair of guide rails for the car, a shaft disposed on the under body of the car, a brake drum fixed on one end of the shaft to rotate with the shaft, a brake shoe mounted on the car, means biasing the brake shoe into frictional engagement 'With the drum, a rack rail movably supported on the car, a rack wheel fixed on the other end of said shaft and in mesh with the rack rail, means for clamping the rack rail to the guide rail so that further down movement of the car will cause rotation of the drum against the brake shoe to decelerate the car, a governor rod for operating the clamping means, and means for movably supporting the governor rod on the car.

15. In an elevator in a hatchway, a car, a pair of guide rails for the car, a shaft disposed on the under body of the car, a brake drum fixed on one end of the shaft to rotate with the shaft, a brake shoe mounted on the car, means biasing the brake shoe into frictional engagement with the drum, a rack rail movably supported on the car, a rack wheel fixed on the other end of said shaft and in mesh with the rack rail, means for clamping the rack rail to the guide rail so that further down movement of the car will cause rotation of the drum against the brake shoe to decelerate the car, a governor rod for operating the clamping means, means for movably supporting the governor rod on the car and a switch responsive to relative movement of the governor rod for controlling operation of the car.

LENNIE R. RISSLER. 

